Periodic remeasurement of the Gus Pearson Natural Area

The 240-acre Gus Pearson Natural Area in Fort Valley Experimental Forest, Arizona, comprises an important historical and ecological site because of the presence of dense stands of old-growth trees and detailed records of stand growth and mortality since 1920. Permanently tagged trees were remeasured after the 2000 growing season. This measurement is the twelfth decadal or bi-decadal measurement since establishment of the study area. This report includes electronic files with tree data and data summaries for selected subplots . Inventory procedures and tree condition codes used in 2000 are documented. The major trends in the 80-year measurement period were: (1) long-term decline in basal area growth, (2) shifts in the relative growth of larger versus smaller trees, and (3) reduced growth and increased mortality, especially since 1945. These trends are consistent with other research findings at the site.